> You should, as early as practical, identify an actual human inside the mothership and convince them to like you.
This presumes humans will retain abilities to manage such decisions, or can manage them at scale in the future. If a company relies on an API for revenue, the best strategy is to have a backup for that API and then a backup for the backup API. A hope-and-a-prayer email address may or may not help retain an existing business relationship, which frankly all depends on the circumstances. Sometimes even a president can't get a company to do something if it is against policy or contrary to revenue.
Assuming connections to people are sufficient to head off changes in business models is a fallacious argument steeped in the idea that VC was a good idea for your company. The VC lead model is the cause of these type of problems, not people who are expected to simultaneously work 20 hour days and still have a life - which is where real connections are formed and retained.
I would have told Dave to go fuck himself.